Aims. We calibrate the number density, completeness, reliability, and the lower mass limit of galaxy-cluster detections through their thermal SZ signal and compare them to X-ray cluster detections.Methods. We simulate maps of the thermal SZ effect and the X-ray emission from light cones constructed in a large, hydrodynamical, cosmological simulation volume, including realistic noise contributions. The maps are convolved with linear, optimised, single- and multi-band filters to identify local peaks and their signal-to-noise ratios. The resulting peak catalogues are then compared to the halo population in the simulation volume to identify true and spurious detections. Results. Multi-band filtering improves the statistics of SZ cluster detections considerably compared to single-band filtering. Observations with the characteristics of ACT detect clusters with masses M ≥ 6-9 × 1013 MȮ/h, quite independent of redshift, reach 50% completeness at ∼ 1014 MȮ/h and 100% completeness at ∼2×. 1014 MȮ/h Samples are contaminated by a few spurious detections, but they are only a small percentage of all detections. This is broadly comparable to X-ray cluster detections with XMM-Newton with 100 ks exposure time in the soft band, except that the mass limit for X-ray detections increases much more steeply with redshift than for SZ detections. A comparison of true and filtered signals in the SZ and X-ray maps confirms that the filters introduce at most a negligible bias. © 2008 ESO.

Statistical properties of SZ and X-ray cluster detections

Pace F.
First
;
2008-01-01

Abstract

Aims. We calibrate the number density, completeness, reliability, and the lower mass limit of galaxy-cluster detections through their thermal SZ signal and compare them to X-ray cluster detections.Methods. We simulate maps of the thermal SZ effect and the X-ray emission from light cones constructed in a large, hydrodynamical, cosmological simulation volume, including realistic noise contributions. The maps are convolved with linear, optimised, single- and multi-band filters to identify local peaks and their signal-to-noise ratios. The resulting peak catalogues are then compared to the halo population in the simulation volume to identify true and spurious detections. Results. Multi-band filtering improves the statistics of SZ cluster detections considerably compared to single-band filtering. Observations with the characteristics of ACT detect clusters with masses M ≥ 6-9 × 1013 MȮ/h, quite independent of redshift, reach 50% completeness at ∼ 1014 MȮ/h and 100% completeness at ∼2×. 1014 MȮ/h Samples are contaminated by a few spurious detections, but they are only a small percentage of all detections. This is broadly comparable to X-ray cluster detections with XMM-Newton with 100 ks exposure time in the soft band, except that the mass limit for X-ray detections increases much more steeply with redshift than for SZ detections. A comparison of true and filtered signals in the SZ and X-ray maps confirms that the filters introduce at most a negligible bias. © 2008 ESO.
2008
Inglese
Esperti anonimi
483
2
389
400
12
Cosmology: cosmic microwave background; Cosmology: theory; Galaxies: clusters: general; Methods: N-body simulations; X-rays: galaxies: clusters
4 – prodotto già presente in altro archivio Open Access (arXiv, REPEC…)
262
7
Pace F.; Maturi M.; Bartelmann M.; Cappelluti N.; Dolag K.; Meneghetti M.; Moscardini L.
info:eu-repo/semantics/article
open
03-CONTRIBUTO IN RIVISTA::03A-Articolo su Rivista
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1842042
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